Year	Percent
1960-01-01	45.3731028942607
1961-01-01	45.6046891104096
1962-01-01	46.6303898285920
1963-01-01	47.9830500866617
1964-01-01	48.8602287330418
1965-01-01	49.3290758117086
1966-01-01	49.0940811230886
1967-01-01	48.8427368569035
1968-01-01	49.3013911085692
1969-01-01	49.8579355486544
1970-01-01	50.1022017097914
1971-01-01	51.1375008994839
1972-01-01	52.1750288384247
1973-01-01	51.6494263333411
1974-01-01	53.2963264705678
1975-01-01	54.1044794612962
1976-01-01	54.0734904289644
1977-01-01	53.1979175523441
1978-01-01	52.5085296678320
1979-01-01	52.2538709275793
1980-01-01	52.2487260894584
1981-01-01	52.1886238417086
1982-01-01	51.7981776045136
1983-01-01	50.8476098078062
1984-01-01	50.9322986527911
1985-01-01	51.0833342895650
1986-01-01	51.1333874210908
1987-01-01	51.1394752172507
1988-01-01	50.9011188983987
1989-01-01	50.3072546651829
1990-01-01	49.7037104350030
1991-01-01	49.1331627411945
1992-01-01	49.1536159353404
1993-01-01	49.6097400447248
1994-01-01	49.7656942886719
1995-01-01	49.9717020563959
1996-01-01	49.9386676946109
1997-01-01	49.6035430718838
1998-01-01	49.8212253570962
1999-01-01	50.3127244358642
2000-01-01	50.6444581353789
2001-01-01	50.7832655017604
2002-01-01	51.4399938219853
2003-01-01	51.6262343636064
2004-01-01	51.7002578328990
2005-01-01	51.5833785988568
2006-01-01	51.5092666005222
2007-01-01	51.5283457291265
2008-01-01	51.5921950385931
2009-01-01	51.4810757561041
2010-01-01	51.5454435345647
2011-01-01	51.8226024438873
2012-01-01	51.8069182172632
2013-01-01	51.0853503616637
2014-01-01	50.6929152315369
2015-01-01	50.3469137336645
2016-01-01	49.6343339158338
2017-01-01	48.8364172096913